During routine maintenance, the movement of a network cable brought to light a dormant issue in one networking component, resulting in a degraded connection. Later, while trying to fix this issue, an unrelated network cable was accidentally disconnected for a few seconds. As our infrastructure is built redundantly, both incidents should have had no impact. However, a software malfunction prevented another connection to take over on both system. This put them into an unstable state that resulted in a partial unavailability of our services between 15:20 and 19:45 CEST.